15972717 has 4 divisors (see below), whose sum is σ = 21296960. Its totient is φ = 10648476.

The previous prime is 15972713. The next prime is 15972731. The reversal of 15972717 is 71727951.

It is a semiprime because it is the product of two primes, and also a Blum integer, because the two primes are equal to 3 mod 4, and also an emirpimes, since its reverse is a distinct semiprime: 71727951 = 3 ⋅23909317.

It is not a de Polignac number, because 15972717 - 2² = 15972713 is a prime.

It is a Duffinian number.

It is a congruent number.

It is not an unprimeable number, because it can be changed into a prime (15972713) by changing a digit.

It is a polite number, since it can be written in 3 ways as a sum of consecutive naturals, for example, 2662117 + ... + 2662122.

It is an arithmetic number, because the mean of its divisors is an integer number (5324240).

Almost surely, 2^15972717 is an apocalyptic number.

It is an amenable number.

15972717 is a deficient number, since it is larger than the sum of its proper divisors (5324243).

15972717 is an equidigital number, since it uses as much as digits as its factorization.

15972717 is an evil number, because the sum of its binary digits is even.

The sum of its prime factors is 5324242.

The product of its digits is 30870, while the sum is 39.

The square root of 15972717 is about 3996.5881699269. The cubic root of 15972717 is about 251.8409017172.

The spelling of 15972717 in words is "fifteen million, nine hundred seventy-two thousand, seven hundred seventeen".